This invention relates to a washer, more particularly to a type of lock washer or anti-slip washer.
The prior art teaches a variety of such type washers, for example, as disclosed in U.S. Pat. Nos. 2,275,315; 2,370,912; 2,518,399; 2,927,495; 3,315,720; 3,476,009; 3,566,738; 3,788,185; and others.